Solenoid valve

Abstract

A solenoid valve comprises a bobbin, a coil, a valve rod, a slidable ring, and a rotatable ring. The bobbin has a through hole. The coil is wound around the bobbin. The valve rod is disposed in the through hole and is inwardly or outwardly movable along the through hole. The slidable ring is telescoped onto the valve rod and inwardly or outwardly movable with the valve rod. The rotatable ring is disposed inside the through hole and inside the slidable ring.

1 . A solenoid valve comprising:
 a bobbin having a through hole;   a coil wound around the bobbin;   a valve rod disposed in the through hole and capable of moving inwardly or outwardly along the through hole;   a slidable ring telescoped onto the valve rod and inwardly or outwardly movable with the valve rod; and   a rotatable ring disposed inside the through hole and the slidable ring.   
   
   
       2 . The solenoid valve as claimed in  claim 1 , wherein the valve rod is a movable iron core. 
   
   
       3 . The solenoid valve as claimed in  claim 1 , wherein the valve rod is maintained in an extended position by an outward thrust of the rotatable ring and in a retracted position by an inward thrust of the slidable ring. 
   
   
       4 . The solenoid valve as claimed in  claim 3 , wherein a bottom of a inner wall of the through hole has an inclined surface, and when the valve rod is located in the retracted position, the rotatable ring engages with the inclined surface and the slidable ring and the valve rod do not sustain the outward thrust,
 wherein the outward thrust is greater than the inward thrust when the valve rod is located in the extended position.   
   
   
       5 . The solenoid valve as claimed in  claim 3 , wherein the outward thrust arises from a spring, and the inward thrust arises from a spring, gravity, or friction. 
   
   
       6 . The solenoid valve as claimed in  claim 3 , wherein the coil is provided with voltage voltage to switch the valve rod between the extended position and the retracted position. 
   
   
       7 . The solenoid valve as claimed in  claim 6 , wherein the excitation voltage is a pulse voltage or a transient digital signal. 
   
   
       8 . The solenoid valve as claimed in  claim 3 , further comprising a first spring disposed in the through hole, outside the slidable ring, and around the valve rod, wherein an end of the first spring is fixed to the bobbin, and the first spring provides the inward thrust on the slidable ring. 
   
   
       9 . The solenoid valve as claimed in  claim 3 , further comprising a second spring disposed in the through hole and inside the rotatable ring and providing the outward thrust on the rotatable ring. 
   
   
       10 . The solenoid valve as claimed in  claim 3 , wherein an inner wall of the through hole of the bobbin have a plurality of rib parts and a plurality of guiding grooves, and the rib parts and the guiding grooves are alternately arranged. 
   
   
       11 . The solenoid valve as claimed in  claim 10 , wherein each of the rib parts has a first rib, a second rib, and a middle rib disposed between the first rib and the second rib, and a bottom of the first rib and the middle rib have a first inclined surface, and the second rib has a second inclined surface. 
   
   
       12 . The solenoid valve as claimed in  claim 11 , wherein the slidable ring has a plurality of the first projections corresponding to the guiding grooves and the middle ribs of the bobbin, respectively, and is outwardly and inwardly slidable along an axial direction of the through hole;
 wherein the slidable ring further has a first teeth part disposed at a bottom of the first projections and provided with a plurality of first toothed tips, and each of the first projections corresponds to each of the first toothed tips.   
   
   
       13 . The solenoid valve as claimed in  claim 12 , wherein the rotatable ring has a second teeth part and a plurality of second projections, the second teeth part has a plurality of second toothed tips engaged with the first teeth part, and the second projections are correspondingly accommodated in the guiding grooves;
 wherein the first teeth part does not engage with the second teeth part when the first projections and the second projections are accommodated in the guiding grooves.   
   
   
       14 . The solenoid valve as claimed in  claim 12 , wherein when the coil is provided with voltage voltage to extract the valve rod, the rotatable ring engages with the slidable ring to rotate an angle. 
   
   
       15 . The solenoid valve as claimed in  claim 13 , wherein the voltage is a pulse voltage or a transient digital signal. 
   
   
       16 . The solenoid valve as claimed in  claim 14 , wherein the first projections and the second projections are accommodated in the guiding grooves when the valve rod is located in the extended position. 
   
   
       17 . The solenoid valve as claimed in  claim 16 , wherein when the valve rod is retracted inwardly due to the excitation voltage, the second projections of the rotatable ring leave the guiding grooves, and then the rotatable ring engages with the slidable ring to rotate an angle. 
   
   
       18 . The solenoid valve as claimed in  claim 17 , wherein when the valve rod moves outwardly, the second projections of the rotatable ring slide along the first inclined surface to rotate another angle, and the second projections are stuck between the first inclined surfaces and the second ribs, and the slidable ring and the valve rod are maintained in the retracted position by the inward thrust. 
   
   
       19 . The solenoid valve as claimed in  claim 14 , wherein when the valve rod is located in the retracted position, the second projections of the rotatable ring are stuck between the first inclined surfaces and the second ribs of the through hole. 
   
   
       20 . The solenoid valve as claimed in  claim 19 , wherein when the valve rod is retracted inwardly due to the voltage, the rotatable ring engages with the slidable ring to rotate an angle, and then when the valve rod moves outwardly, the second projections of the rotatable ring slide along the second inclined surface to rotate another angle, and the second projections slide into the guiding grooves, and then the rotatable ring, the slidable ring, and the valve rod are maintained in the extended position by the outward thrust.